Triazapentadienes as acaricides

ABSTRACT

Certain heteroaryl triazapentadienes with acaricidal properties and their preparation are described.

BACKGROUND OF THE INVENTION

All stages in the life cycle of ticks tend to damage the skins ofafflicted animals and thereby spoil the state of the skins with theconsequence that cattle hides and sheep skins intended for themanufacture of leather and sheep skin are reduced in quality.Furthermore, the ticks may facilitate the transmission of disease to theafflicted animal, and the general state of health and the quality offlesh of the animal may be detrimentally affected.

Belgian Pat. No. 816,760 describes certain 5-(substitutedphenyl)-3-(alkyl)-1-(alkyl)-1,3,5-triazapenta-1,4-dienes as broadspectrum parasiticides.

We have now found that certain 5-(substitutedphenyl)-3-methyl-1-(heteroaryl)-triazapenta-1,4-dienes have particularlyuseful acaricidal properties, and are thus very useful in destroying oneor more stages in the life cycle of ticks which tend to infest the skinsof animals such as cattle. They may also have insecticidal properties,particularly against plant insects such as pea aphids (hemiptera).

SUMMARY OF THE INVENTION

This invention is concerned with triazapentadienes of the formula:##STR1## wherein R¹ is a C₁ -C₄ alkyl group;

R² is a hydrogen atom, a halogen atom or a C₁ -C₄ alkyl group;

R³ is a monocyclic or bicyclic heteroaryl group attached to the adjacentnitrogen atom by a carbon atom of said group;

And R⁴ is a hydrogen atom or a C₁ -C₄ alkyl group;

And the acid addition salts of the compounds of the formula (I) whichform such salts.

DETAILED DESCRIPTION OF THE INVENTION

In this specification the term "halogen" means fluorine, chlorine,bromine or iodine.

Alkyl groups containing three or more carbon atoms may be straight orbranched chain. The preferred alkyl groups contain 1 or 2 carbon atoms.

R¹ is preferably a methyl group.

R² is preferably a methyl group or a chlorine atom.

R² is most preferably methyl.

Generally, the preferred heteroaryl groups within the scope of R³ arethose including at least one ring nitrogen atom, such as quinolyl,isoquinolyl, pyridyl, pyrimidinyl, quinazolinyl, quinoxalinyl,tetrazolyl, thiazolyl, benzothiazolyl, 4,5,6,7-tetrahydrobenzothiazolyl,thiadiazolyl, indazolyl, oxazolyl, benzoxazolyl, pyridazinyl andpyrazinyl. However, benzothienyl is also a preferred heteroaryl groupwithin the scope of R³.

The heteroaryl group represented by R³ may be substituted orunsubstituted. Preferred substituents are C₁ -C₆ alkyl, C₁ -C₆ alkoxy,di(C₁ -C₄ alkoxy) methyl, (C₁ -C₄ alkoxy) carbonyl, halogen,trifluoromethyl, phenyl, and C₂ -C₅ alkanoyl. Preferred alkoxy groupscontain 1 or 2 carbon atoms and preferred alkanoyl groups 2 or 3 carbonatoms.

The more preferred heteroaryl groups are quinolyl, isoquinolyl, pyridyl,quinoxalinyl, pyridazinyl, pyrimidinyl, pyrazinyl, indazolyl,tetrazolyl, thiazolyl, benzothiazolyl, 4,5,6,7-tetrahydrobenzothiazolyland benzothienyl optionally containing one or two substituents selectedfrom C₁ -C₄ alkyl, C₁ -C₄ alkoxy, phenyl, di(C₁ -C₄ alkoxy) methyl, (C₁-C₄ alkoxy)carbonyl and halogen.

The most preferred heteroaryl groups are thiazolyl, pyridyl, quinolyl,pyrazinyl, pyridazinyl, quinoxalinyl, benzothiazolyl and benzothienyloptionally containing one or two substituents selected from halogen, C₁-C₄ alkyl and C₁ -C₄ alkoxy.

R⁴ is preferably a hydrogen atom.

The preferred individual compounds are as follows:

5-(2,4-dimethylphenyl)-3-methyl-1-(2-thiazolyl)-1,3,5-triazapenta-1,4-diene

5-(2,4-dimethylphenyl)-3-methyl-1-(2-pyridyl)-1,3,5-triazapenta-1,4-diene

5-(2,4-dimethylphenyl)-3-methyl-1-(3-quinolyl)-1,3,5-triazapenta-1,4-diene

5-(2,4-dimethylphenyl)-3-methyl-1-(3-ethyl-6-methyl-pyrid-2-yl)-1,3,5-triazapenta-1,4-diene

5-(2,4-dimethylphenyl)-3-methyl-1-(3-ethyl-pyrid-2-yl)-1,3,5-triazapenta-1,4-diene

5-(2,4-dimethylphenyl)-3-methyl-1-(3-methyl-pyrid-2-yl)-1,3,5-triazapenta-1,4-diene

5-(2,4-dimethylphenyl)-3-methyl-1-(2,5-dimethyl-pyrid-3-yl)-1,3,5-triazapenta-1,4-diene

5-(2,4-dimethylphenyl)-3-methyl-1-(2-chloro-pyrid-3-yl)-1,3,5-triazapenta-1,4-diene

5-(2,4-dimethylphenyl)-3-methyl-1-(2-pyrazinyl)-1,3,5-triazapenta-1,4-diene

5-(2,4-dimethylphenyl)-3-methyl-1-(6-methoxy-pyridazin-3-yl)-1,3,5-triazapenta-1,4-diene

5-(2,4-dimethylphenyl)-3-methyl-1-(6-quinolyl)-1,3,5-triazapenta-1,4-diene

5-(2,4-dimethylphenyl)-3-methyl-1-(6-quinoxalinyl)-1,3,5-triazapenta-1,4-diene

5-(2,4-dimethylphenyl)-3-methyl-1-(3,6-dimethyl-pyrid-2-yl)-1,3,5-triazapenta-1,4-diene

5-(2,4-dimethylphenyl)-3-methyl-1-(3,5-dimethyl-pyrid-2-yl)-1,3,5-triazapenta-1,4-diene

5-(2,4-dimethylphenyl)-3-methyl-1-(3-n-propyl-pyrid-2-yl)-1,3,5-triazapenta-1,4-diene

5-(2,4-dimethylphenyl)-3-methyl-1-(3-n-butyl-pyrid-2-yl)-1,3,5-triazapenta-1,4-diene

5-(2,4-dimethylphenyl)-3-methyl-1-(6-benzothiazolyl)-1,3,5-triazapenta-1,4-diene

5-(2,4-dimethylphenyl)-3-methyl-1-(6-benzothienyl)-1,3,5-triazapenta-1,4-diene

5-(2,4-dimethylphenyl)-3-methyl-1-(3,4-dimethyl-pyrid-2-yl)-1,3,5-triazapenta-1,4-diene.

The compounds of the invention may be prepared via a number of routes,including the following:

(1) Compounds in which R⁴ is hydrogen may be prepared by reacting aformamidine of the formula: ##STR2## with an isonitrile of the formulaR³.NC. R¹, R² and R³ are as defined for formula (I).

The reaction may be effected in the presence of a suitable catalyst,most preferably finely divided copper metal or a cuprous catalyst suchas cuprous oxide or cuprous chloride in a trace amount, a typicalreaction temperature being 50° to 80° C. Increased reaction temperaturesare not generally recommended because they tend to increase theformation of by-products due to the reaction of one molecule of compound(II) with another such molecule. The reaction may be effected in thepresence of a suitable inert organic solvent, such as benzene ortoluene.

Generally, long reaction times are necessary unless finely dividedcopper metal is used as the catalyst.

Typically, the product is recovered by evaporation of the reactionmixture in vacuo to leave an oil which may, if necessary, be purified bya conventional procedure such as treatment with neutral alumina in40°-60° petroleum ether. The purified oil may crystallise on standing togive crystals of the desired product of the formula (I).

The isonitriles of the formula R³.NC and the formamidines of the formula(II) are either known compounds or may be prepared by proceduresanalogous to those of the prior art. Methods for the preparation offormamidines falling within the formula (II) are described for examplein British Patent Specification No. 964,640, 1,039,930 and 1,327,936.

(2) The following route, in which R⁴ may be hydrogen or C₁ -C₄ alkyl, isalso possible: an imidate of the formula: ##STR3## wherein R¹ and R² areas defined for formula (I) and R⁵ is a C₁ -C₄ alkyl group, is reactedwith an amidine of the formula: ##STR4## wherein R³ and R⁴ are asdefined for formula (I).

(3) Compounds of the formula (I) in which R⁴ is a hydrogen atom or a C₁-C₄ alkyl group may be prepared by reacting an amidine of the formula:##STR5## wherein R³ and R⁴ are as defined for formula (I), with anisonitrile of the formula: ##STR6## wherein R¹ and R² are as defined forformula (I).

The reaction and isolation of the product may be carried out in asimilar manner to method (1) above, although in this case it isgenerally possible to use reaction temperatures of above 80° C. withoutsubstantially increasing the formation of by-products, reactiongenerally being substantially complete within 4-8 hours at 100° C.except when using finely divided copper metal as the catalyst in whichcase the reaction is generally complete in 1-2 hours.

This is a preferred route. The starting materials of the formula (IV)are either known compounds or may be obtained in a conventional manner,e.g. as follows: ##STR7##

(4) The compounds of the formula (I) in which R⁴ is a hydrogen atom or aC₁ -C₄ alkyl group may also be prepared by reacting a formamidine of theformula: ##STR8## wherein R¹ and R² are as defined for formula (I), withan imidate of the formula: ##STR9## wherein R³ and R⁴ are as defined forformula (I) and R⁶ is a C₁ -C₄ alkyl group. R⁶ is preferably an ethylgroup.

The reaction is typically carried out by heating the reactants togetherfor several hours, e.g. at 40°-100° C. for 2-4 hours. Alternatively asolvent, e.g. iso-octane, may be used. The product typicallycrystallises on cooling and may be purified by crystallisation from e.g.hexane, cyclohexane or mixed solvents, e.g. methylene chloride/hexane.Treatment with decolouring carbon during crystallisation may bebeneficial.

This is a preferred route.

The imidates of the formula (VI) are either known compounds or may beobtained in a conventional manner, e.g. as follows: ##STR10##

(5) The acid-addition salts of the compounds of the formula (I) whichform such salts may be made in a conventional manner, e.g. by mixing asolution of the free base in a suitable solvent, e.g. diethyl ether,with a solution of the appropriate acid in a suitable solvent, e.g.diethyl ether, and recovering the salt as a precipitate.

The compounds of the formula (I) have acaricidal activity, particularlyagainst all stages in the life cycle, including gravid female ticks, ofthe cattle ticks Boophilus microplus, Haemaphysalis longicornus,Rhipicophalus appendiculatus and Boophilus decoloratus.

In one test, five freshly collected, fully engorged Boophilus microplusadult female ticks are used for each acaricidal compound. Using amicro-pipette 10 micro-liters of a solution containing 10 micro-grams ofthe acaricidal compound in ethanol or acetone, is applied to the dorsalsurface of each of the ticks. The treated ticks are placed in weighed 1× 2 inch glass vials, weighed and stored at 26° C. and 80% + R.H. inplastic boxes for two weeks. The ticks are then removed from the vialsand the vials weighed to give the weight of eggs laid by the ticks. Anyreduction in the egg laying of the treated ticks is calculated as apercentage of the eggs laid by untreated control ticks.

The eggs are returned to the incubator for a further 3 weeks after whichtime the percentage of eggs hatching is estimated.

The percentage reduction in the anticipated reproduction of the ticks iscalculated using the weight of eggs laid and the percentage of eggshatching.

The test may be repeated using smaller amounts of the acaricidalcompound.

In another test, using a pipette 0.5 ml of a solution containing 0.5 mgof the acaricidal compound in ethanol or acetone is spread evenly on toa Whatman No. 1 filter paper 8 cm × 6.25 cm (50 sq. c.m.) to give adosage of 100 mg/m².

The treated paper is allowed to dry at room temperature, folded with thetreated surface inside and two short edges sealed with a crimpingmachine. The open ended envelope is placed in a 1lb Kilner jarcontaining damp cotton wool in a plastic pot and stored in an incubatorat 26° C. for 24 hours. 20-50 Boophilus microplus larvae, which hadhatched 8-14 days previously, are placed in the envelope using a smallspatula. The open end is then crimped to form a sealed packet. Thetreated paper containing the larvae is returned to the Kilner jar andkept for a further 48 hours in the incubator. 20-50 larvae are placedsimilarly in an untreated paper envelope to act as controls. At the endof the 48 hour test period the mortality is noted and recorded as apercentage after correction for any mortality among the untreatedcontrol ticks.

The test may be repeated using smaller amounts of the acaricidalcompound.

In addition to percentage effectiveness figures, ED₅₀ results can beobtained from dose response measurements using any of theafore-described tests.

Activity against Haemaphysalis longicornus nymphs may be measured in asimilar manner to the above larvae test.

The activity of certain of the compounds of the Examples detailedhereinafter against the tick Boophilus microplus is set out in thefollowing Table:

                  TABLE                                                           ______________________________________                                        Boophilus Microplus (in vitro)                                                Larva (Contact)    Adult (Topical)                                            Compound                                                                              Dose       %       Dose    % Reduction                                No.     (mg/m.sup.2)                                                                             Kill    (μg/tick)                                                                          in Egg Hatch                               ______________________________________                                        1              100     100   10      100                                      and                                                                           90             12.5    100    2      99                                       2              100     100   10      99                                       and                                                                           91             6.25    100    4      93                                       3              100     100   10      99                                                      12.5     94    2      96                                       4              100     100   10      100                                                     12.5    100    2      97                                       5              100     100   10      100                                                     12.5    100    4      88                                       6              100     100   10      100                                                     6.25    100    4      86                                       7              100     100   10      89                                                      12.5    100                                                    8              100     100   10      90                                                      25      100                                                    9              100     100   10      53                                                      25       86                                                    10             100     100   10      92                                                      25       89                                                    11             100     100   10      92                                                      6.25    100                                                    12             100      78   --      --                                       13             100      31    8      68                                       14             100     100   10      100                                                     3.13     90    4      97                                       15             100     100   10      100                                                     3.13    100    4      83                                       16             100     100   10      100                                      and                                                                           92             3.13     98    2      95                                       17             100     100   10      100                                                     6.25    100    2      67                                       18             100      56   10      100                                      and                                                                           76                            4      99                                       20             100     100   10      29                                                      12.5    100                                                    21             100      86   10      58                                       22             100      90   10      99                                                                     4      97                                       23             100     100   10      85                                                      12.5    100                                                    24             100     100   10      100                                                     12.5     83    2      90                                       25             100     100   10      100                                                     12.5     88    2      91                                       26             100     100   10      100                                                     25       98    8      98                                       27             100      85   10      53                                       28             100     100   10      100                                                     50       98    2      99                                       29             100     100    2      20                                                      50       82                                                    30             100     100   10      78                                                      25       92                                                    31             100     100   10      94                                                      6.25     83                                                    32             100      17   10      59                                       33             100      33   10      100                                                                    4      98                                       34             100     100   10      93                                       35             100     100   10      13                                                      25       83                                                    36             100     100   10      16                                       37             100      32   10      100                                                                    4      90                                       38             100     100   10      72                                                      6.25     94                                                    39             100     100   10      96                                                      12.5     98                                                    40             100      14    8      100                                                                    4      81                                       41             100     100   10      100                                      42             100     100   10      25                                                      12.5    100                                                    43             100      97   10      100                                                     12.5    100                                                    44             100     100   10      97                                                      6.25     84                                                    45             100     100   10      100                                                     6.25    100                                                    46             100     100   10      22                                       47             100     100   10      28                                       48             100      92   10      100                                                                   8       91                                       50             100     100   10      95                                                      25      100   8       94                                       51             100     100   10      93                                       52             100     100   10      18                                                      50      100                                                    54             100      80   10      55                                       55             100     100   10      26                                                      12.5    100                                                    56             100     100   10      85                                                      25       73                                                    57             100      80   10      89                                       58             100      97   10      96                                                      25       79                                                    59             100     100   10      66                                                      25       68                                                    60             100      94   10      28                                                      25       88                                                    62             100      98   10      88                                                      50       60                                                    63             100     100   10       7                                                      12.5    100                                                    65             100     100   10      100                                                     12.5     76    1      97                                       66             100     100   10      100                                                     --      --     1      90                                       67             100      84   10      98                                                      --      --     4      58                                       68             100      69   10      100                                                     --      --     4      84                                       69             100      24   10      99                                       70             100     100   10      100                                                     3.12     95    1      31                                       71             100      85   10      89                                                      --      --     4      57                                       72             100     100   10      99                                                      1.56     73    2      22                                       73             100     100   10      91                                                      12.5    100    2      69                                       74             100      66   10      99                                                      --      --     4      52                                       77             100     100   10      100                                                     12.5     89    2      71                                       78             100      91   10      100                                                                    2      97                                       79             100     100   10      100                                                     50       35    1      83                                       80             100      59   10      100                                                                    2      98                                       83             100      85   10      100                                                                    1      97                                       ______________________________________                                    

Thus the invention also provides an acaricidal composition comprising acompound of the formula (I) together with a diluent or carrier. Thediluent or carrier may be a solid or a liquid, optionally together withan antioxidant, dispersing agent, emulsifying agent or wetting agent.The compositions of the invention include not only compositions in asuitable form for application but concentrated primary compositionswhich may be supplied to the user and which require dilution with asuitable quantity of water or other diluent prior to application.Typical compositions of the invention include, for example, dustingpowders, dispersible powders, dispersions, emulsions and emulsifiableconcentrates.

A dust may be made by mixing the appropriate amount of the finelydivided active compound with a solid pulverent diluent or carrier suchas talc, clay, calcite, pyrophyllite, diatomaceous earth, walnut shellflour, silica gel, hydrated alumina, or calcium silicate. As analternative method of preparation, the diluent or carrier is mixed witha solution of the active compound in a volatile organic solvent such asbenzene, the solvent being subsequently removed by evaporation.Typically, the active compound will be present in the dust in an amountof from 0.25 to about 4% by weight.

Dispersible powders may be made by adding a suitable dispersing agent tothe active compound, or to a dust containing the active compound, sothat a stable aqueous dispersion of the active compound is formed onmixing the powder with water. The dispersible powders preferably containfrom about 25 to 75% by weight of the active compound.

Emulsifiable concentrates comprise a solution of the active compound ina substantially water-immiscible non-toxic organic solvent containing anemulsifying agent. Suitable solvents include, for example, toluene,xylene, petroleum oil, and alkylated naphthalenes. Preferably, theconcentrate will contain 5-75 gms. of the active compound per 100 ml. ofsolution. The concentrates may be diluted with water prior to use togive a typical concentration of the active compound in the aqueousmedium of from e.g. about 0.001 to about 0.1% w/v (g/100 ml.), orapproximately 10 to 1000 p.p.m. The volatile solvents, e.g. toluene andxylene, evaporate after spraying to leave a deposit of the activeingredient. The made up spray or dip will generally be an emulsion.

The compositions of the invention may be applied to ground, such as thataround dairies, in order to combat e.g. cattle ticks thereon. However,it is preferred to treat animals by spraying them or passing themthrough animal dips.

Thus the present invention also provides a method for protectinganimals, particularly cattle, from acarids, particularly cattle ticks,which comprises treating the animal externally with an acaricidal amountof a compound of the formula (I) or acaricidal composition as definedabove.

The compositions of the invention may also contain a pesticide,fungicide, additional acaricide, or the like.

The invention is illustrated by the following Examples, in which alltemperatures are given in ° C. The compounds of the invention werecharacterised by infra-red and nuclear magnetic resonance (n.m.r.)spectra, thin layer chromatography, and, in most cases, by meltingpoint, analytical and mass spectral data. In the n.m.r. data, theprotons responsible for the signals are underlined, s, q, t and mindicating, respectively, a singlet, quartet, triplet and multiplet.

EXAMPLE 1 Preparation of5-(2,4-dimethylphenyl)-3-methyl-1-(2-pyridyl)-1,3,5-triazapenta-1,4-diene##STR11##

A mixture of N-methyl-N'-(2-pyridyl)-formamidine (2.5 g, 0.0185 m),2,4-dimethylphenylisocyanide (2.4 g, 0.0185 m), cuprous oxide (traceamount) and dry toluene (60 ml) was heated on a steam bath withoccasional agitation for 4 hours. The reaction mixture was then cooled,filtered through "Hyflo" (diatomaceous earth) and alumina, and thetoluene filtrate evaporated to dryness in vacuo to yield a viscous oil.The oil was triturated with 60°-80° petroleum ether to yield a whitesolid. Crystallisation of this solid from ether/60° -- 80° petroleumether yielded the product,5-(2,4-dimethylphenyl)-3-methyl-1-(2-pyridyl)-1,3,5-triazapenta-1,4-diene,(1.0 g) m.p. 100°.

Analysis %: Found: C, 71.84; H, 6.52; H, 20.59. C₁₆ H₁₈ N₄ requires: C,72.15; H, 6.81; H, 21.04.

EXAMPLES 2 TO 75

The following compounds were prepared by procedures similar to that ofExample 1, starting from 2,4-dimethylphenylisocyanide or4-chloro-2-methylphenylisocyanide and the appropriate amidine of theformula R³.N═C(R⁴).NHCH₃. ##STR12##

    __________________________________________________________________________                                                 Analysis %                                                                    (Theoretical in                  __________________________________________________________________________                                                 brackets)                                                               m.p.  C     H     N                    Compound No.                                                                          R.sup.2                                                                            R.sup.3              R.sup.4                                                                            (° C)                                                                        (or n.m.r. and mass spectral                                                  data)                            __________________________________________________________________________    2       CH.sub.3                                                                                                H    76 - 79                                                                             71.68 (71.83                                                                        6.71 6.63                                                                           16.88 16.75)*        3       CH.sub.3                                                                            ##STR13##           H    86 - 88                                                                             71.79 (72.15                                                                        6.96 6.81                                                                           20.36 21.07)         4       CH.sub.3                                                                            ##STR14##           H    115 - 116                                                                           73.00 (73.44                                                                        7.45 7.53                                                                           18.76 19.03)         5       CH.sub.3                                                                            ##STR15##           H    98    63.77 (63.87                                                                        5.51 5.78                                                                           18.85 18.63)         6       CH.sub.3                                                                            ##STR16##           H    104 - 5                                                                             71.98 (72.15                                                                        6.79 6.81                                                                           20.97 21.07)         7       Cl                                                                                  ##STR17##           H    112   62.64 (62.82                                                                        5.12 5.27                                                                           19.19 19.54)         8       Cl                                                                                  ##STR18##           H    138 - 140                                                                           63.02 (62.82                                                                        5.11 5.27                                                                           19.27 19.54)         9       Cl                                                                                  ##STR19##           H    84 - 86                                                                             56.05 (56.09                                                                        4.04 4.39                                                                           17.30 17.44)         10      Cl                                                                                  ##STR20##           H    93 - 96                                                                             58.72 (58.87                                                                        5.50 5.52                                                                           15.93 16.16)         11      Cl                                                                                  ##STR21##           H    75 - 79                                                                             62.70 (62.82                                                                        5.35 5.27                                                                           20.09 19.54)         12      CH.sub.3                                                                            ##STR22##           CH.sub.3                                                                           oil                                                                                  ##STR23##                       13      CH.sub.3                                                                            ##STR24##           C.sub.2 H.sub.5                                                                    oil                                                                                  ##STR25##                       14      CH.sub.3                                                                            ##STR26##           H    125   64.15 (63.90                                                                        5.63 5.66                                                                           18.68 18.64)         15      Cl                                                                                  ##STR27##           H    152   56.49 (56.07                                                                        4.44 4.36                                                                           17.78 17.45)         16      CH.sub.3                                                                            ##STR28##           H    80    74.08 (74.00                                                                        7.89 7.84                                                                           18.11 18.17)         17      Cl                                                                                  ##STR29##           H    85    65.61 (65.74                                                                        6.49 6.44                                                                           16.91 17.04)         18**    CH.sub.3                                                                            ##STR30##           H    99 - 100                                                                            61.36 (61.74                                                                        5.81 5.92                                                                           21.18 20.57)         19      CH.sub.3                                                                            ##STR31##           H    133 - 136                                                                           67.72 (67.05                                                                        5.69 5.63                                                                           17.52 17.38          20      CH.sub.3                                                                            ##STR32##           H    151 - 153                                                                           57.01 (57.32                                                                        4.85 4.81                                                                           16.72 16.71)         21      CH.sub.3                                                                            ##STR33##           H    129 - 131                                                                           69.40 (69.58                                                                        6.11 6.12                                                                           15.50 15.46)         22      CH.sub.3                                                                            ##STR34##           H    96 - 98                                                                             76.02 (75.92                                                                        6.32 6.37                                                                           17.85 17.71)         23      Cl                                                                                  ##STR35##           H    110   67.88 (67.75                                                                        5.01 5.09                                                                           16.75 16.63)         24      CH.sub.3                                                                            ##STR36##           H    129 - 130                                                                           73.25 (73.44                                                                        7.53 7.53                                                                           19.25 19.03)         25      CH.sub.3                                                                            ##STR37##           H    104 - 5                                                                             71.85 (71.90                                                                        5.88 6.03                                                                           21.53 22.07)         26      Cl                                                                                  ##STR38##           H    132 - 4                                                                             63.89 (64.00                                                                        4.78 4.77                                                                           20.67 20.73)         27      CH.sub.3                                                                            ##STR39##           CH.sub.3                                                                           76 - 8                                                                              73.77 (73.99                                                                        7.75 7.84                                                                           18.02 18.17)         28      CH.sub.3                                                                            ##STR40##           H    150 - 151                                                                           64.59 (64.63                                                                        6.30 6.44                                                                           23.03 23.55)         29      Cl                                                                                  ##STR41##           CH.sub.3                                                                           Oil                                                                                  ##STR42##                       30      Cl                                                                                  ##STR43##           H    62 - 4                                                                              53.22 (53.33                                                                        4.52 4.48                                                                           19.52 19.14)         31      Cl                                                                                  ##STR44##           H    128 - 9                                                                             58.24 (58.44                                                                        4.88 4.90                                                                           24.16 24.34)         32      CH.sub.3                                                                            ##STR45##           CH.sub.3                                                                           100 - 101                                                                           67.24 (67.04                                                                        7.07 7.11                                                                           16.52 16.46)         33      Cl                                                                                  ##STR46##           H    130 - 131                                                                           59.52 (59.56                                                                        4.39 4.41                                                                           16.40 16.34)         34      Cl                                                                                  ##STR47##           C.sub.2 H.sub.5                                                                    70    64.71 (64.86                                                                        6.09 6.08                                                                           17.40 17.80)         35      CH.sub.3                                                                            ##STR48##           CH.sub.3                                                                           142   72.86 (72.83                                                                        7.28 7.19                                                                           20.18 19.98)         36      Cl                                                                                  ##STR49##           CH.sub.3                                                                           97    63.63 (63.89                                                                        5.76 5.57                                                                           18.74 18.63)         37      CH.sub.3                                                                            ##STR50##           H    129 - 130                                                                           67.41 (67.19                                                                        6.23 6.41                                                                           25.56 26.20)         38      Cl                                                                                  ##STR51##           H    148   56.29 (56.69                                                                        5.01 5.07                                                                           21.83 22.04)         39      CH.sub.3                                                                            ##STR52##           C.sub.2 H.sub.5                                                                    85    73.16 (73.44                                                                        7.70 7.53                                                                           18.75 19.03)         40      CH.sub.3                                                                            ##STR53##           H    69 - 72                                                                             67.45 (67.79                                                                        7.07 7.17                                                                           17.40  17.19)        41      Cl                                                                                  ##STR54##           H    Oil                                                                                  ##STR55##                       42      CH.sub.3                                                                            ##STR56##           H    134 - 5                                                                             68.57 (68.94                                                                        5.90 5.79                                                                           15.96 16.08)         43      CH.sub.3                                                                            ##STR57##           H    107 - 8                                                                             63.14 (62.91                                                                        6.27 6.33                                                                           19.78 19.56)         44      Cl                                                                                  ##STR58##           H    108 - 9                                                                             61.47 (61.87                                                                        4.64 4.65                                                                           15.43 15.19)         45      Cl                                                                                  ##STR59##           H    Oil                                                                                  ##STR60##                       46      Cl                                                                                  ##STR61##           CH.sub.3                                                                           96 - 97                                                                             54.83 54.81                                                                         4.93 4.93                                                                           18.00 18.26)         47      CH.sub.3                                                                            ##STR62##           CH.sub.3                                                                           105   62.66 (62.91                                                                        6.39 6.34                                                                           20.17 19.56)         48      Cl                                                                                  ##STR63##           H    87 - 9                                                                              54.46 (54.81                                                                        4.88 4.93                                                                           17.80 18.26)         49      CH.sub.3                                                                            ##STR64##           CH.sub.3                                                                           --    --    --    --                   50      CH.sub.3                                                                            ##STR65##           CH.sub.3                                                                           68 - 70                                                                             64.31 (63.97                                                                        6.87 6.71                                                                           19.32 18.65)         51      Cl                                                                                  ##STR66##           CH.sub.3                                                                           77 - 8                                                                              55.96 (56.15                                                                        5.53 5.34                                                                           21.07 17.46)         52      CH.sub.3                                                                            ##STR67##           CH.sub.3                                                                           99    67.90 (68.30                                                                        6.85 6.81                                                                           24.29 24.89)         53      Cl                                                                                  ##STR68##           CH.sub.3                                                                           124   59.30 (59.70                                                                        5.34 5.34                                                                           23.13 23.21)         54      CH.sub.3                                                                            ##STR69##           CH.sub.3                                                                           145   65.04 (65.57                                                                        7.02 6.80                                                                           22.24 22.46)         55      Cl                                                                                  ##STR70##           CH.sub.3                                                                           149 - 150                                                                           57.54 (57.92                                                                        5.73 5.47                                                                           21.61 21.11)         56      Cl                                                                                  ##STR71##           H    53    50.96 (51.07                                                                        5.10 5.28                                                                           32.57 32.07)         57      CH.sub.3                                                                            ##STR72##           H    86    58.76 (58.93                                                                        6.97 6.71                                                                           35.40 34.36)         58      CH.sub.3                                                                            ##STR73##           H    126 - 128                                                                           63.90 (63.97                                                                        6.67 6.71                                                                           18.26 18.65)         59      Cl                                                                                  ##STR74##           H    120 - 122                                                                           56.14 (56.15                                                                        5.31 5.34                                                                           17.53 17.46)         60      CH.sub.3                                                                            ##STR75##           CH.sub.3                                                                           112 - 114                                                                           64.44 (64.94                                                                        6.92 7.05                                                                           17.64 17.82)         61      Cl                                                                                  ##STR76##           CH.sub.3                                                                           135 - 6                                                                             57.22 (57.39                                                                        5.65 5.72                                                                           16.64 16.73)         62      CH.sub.3                                                                            ##STR77##           H    121 - 122                                                                           59.11 (59.28                                                                        6.00 5.85                                                                           16.67 16.27)         63      Cl                                                                                  ##STR78##           H    110 - 111                                                                           62.79 (62.74                                                                        4.78 5.00                                                                           14.57 14.63)         64      Cl                                                                                  ##STR79##           CH.sub.3                                                                           90 - 92                                                                             62.82 (63.54                                                                        5.41 5.33                                                                           13.95 14.11)         65      CH.sub.3                                                                            ##STR80##           H    84 - 86                                                                             72.66 (72.83                                                                        7.12 7.19                                                                           19.98 19.98)         66      CH.sub.3                                                                            ##STR81##           H    105 - 107                                                                           72.51 (72.83                                                                        7.08 7.19                                                                           19.82 19.98)         67      Cl                                                                                  ##STR82##           H    92 - 94                                                                             63.36 (63.89                                                                        5.90 5.70                                                                           18.81 18.63)         68      CH.sub.3                                                                            ##STR83##           H    146 - 147                                                                           75.52 (75.92                                                                        6.49 6.37                                                                           18.08 17.71)         69      CH.sub.3                                                                            ##STR84##           H    87 - 89                                                                             73.04 (72.83                                                                        7.40 7.19                                                                           20.21 19.98)         70      Cl                                                                                  ##STR85##           H    103 - 4                                                                             64.21 (63.89                                                                        5.82 5.70                                                                           19.01 18.63)         71      Cl                                                                                  ##STR86##           H    124 - 5                                                                             67.66 (67.75                                                                        5.24 5.09                                                                           16.60 16.63)         72      Cl                                                                                  ##STR87##           H    129 - 130                                                                           63.78 (63.89                                                                        5.77 5.70                                                                           19.01 18.63)         73      CH.sub.3                                                                            ##STR88##           H    122 - 5                                                                             72.94 (72.83                                                                        7.13 7.19                                                                           20.78 19.98)         74      Cl                                                                                  ##STR89##           H    99.5 - 101.5                                                                        64.42 (63.89                                                                        5.75 5.70                                                                           18.66 18.63)         75      CH.sub.3                                                                            ##STR90##           H    Oil   n.m.r.: δ = 1.23 (t,                                                    6H), 2-CH.sub.2 CH.sub.3 ;                                                    2.30 (s, 6H) 2 aromatic                                                       CH.sub.3 groups 3.53 (s) N .                                                  CH.sub.3  . Molecular weight                                                  from mass spectral data          __________________________________________________________________________                                                 407.                              *this compound was isolated as the monohydrate, and the theoretical           analysis calculated accordingly.                                              **This experiment was repeated under similar conditions but using a trace     amount of finely-divided copper metal in place of cuprous oxide as the        catalyst.                                                                

EXAMPLE 76 Preparation of5-(2,4-Dimethylphenyl)-3-methyl-1-(2-thiazolyl)-1,3,5-triazapenta-1,4-dien##STR91## A mixture of N-methyl-N'-(2,4-dimethylphenyl)-formamidine(188.8 g) and ethyl N-(2-thiazolyl)-formimidate (200.0 g) was heated to75° for 2 hours under water-pump pressure. Ethanol began to distilshortly after heating commenced and ceased after approximately 1 hour.On cooling, the mixture solidified. Crystallisation from n-hexane andrecrystallisation from methylene chloride/hexane with decolourisingcarbon treatment afforded 295 g of product in two crops. (Yield 93%). Aportion was further recrystallised from cyclohexane to provide ananalytical sample, m.p. 101°.

Analysis %: Found: C, 61.62; H, 5.96; N, 21.23. Calculated for C₁₄ H₁₆N₄ S: C, 61.73; H, 5.92; N, 20.57%.

The product was identical to the product of Example 18.

EXAMPLE 77-93

The following compounds were prepared similarly to Example 76, startingfrom N-methyl-N'-(2,4-dimethylphenyl)formamidine and the appropriateformimidate of the formula R³.N═CH.OC₂ H₅.

    __________________________________________________________________________     ##STR92##                                                                                                 Analysis %                                                                    (Theoretical in brackets)                        Compound                m.p. C                                                No.   R.sup.2                                                                          R.sup.3      R.sup.4                                                                         (° C)                                                                       (or n.m.r.)                                                                         H     N                                    __________________________________________________________________________    77    CH.sub.3                                                                          ##STR93##   H 134-5                                                                               67.00 (67.39                                                                       6.28 6.41                                                                           27.03 26.20)                         78    CH.sub.3                                                                          ##STR94##   H  89  76.34 (75.92                                                                        6.32 6.37                                                                           17.67 17.71)                         79    CH.sub.3                                                                          ##STR95##   H 64-5 n.m.r. (CDCl.sub.3) δ = 2.26 (s, 6H),                                   2 aromatic CH.sub.3 groups; 3.43 (s, 3H),                                     NCH.sub.3. Molecular weight from mass                                         spectral data 321.                               80    CH.sub.3                                                                          ##STR96##   H oil  This compound was a monohydrate. 63.51                                        5.7015.51 (63.505.9216.46) Molecular weight                                   from mass spectral data 322.                     81    CH.sub.3                                                                          ##STR97##   H 135  66.04 (66.23                                                                        6.71 6.79                                                                           17.24 17.16)                         82    CH.sub.3                                                                          ##STR98##   H 97-8 73.14 (73.44                                                                        7.63 7.53                                                                           19.10 19.03)                         83    CH.sub.3                                                                          ##STR99##   H 91-3 75.51 (73.44                                                                        7.37 7.53                                                                           18.87 19.03)                         84    CH.sub.3                                                                          ##STR100##  H 148-150                                                                            57.31 4.56 4.81                                                                           16.79 16.71)                         85    CH.sub.3                                                                          ##STR101##  H 129  55.62 (55.66                                                                        4.85 4.96                                                                           16.22 16.23)                         86    CH.sub.3                                                                          ##STR102##  H 104  73.05 (73.44                                                                        7.40 7.53                                                                           18.78 19.03)                         87    CH.sub.3                                                                          ##STR103##  H 70-71                                                                              73.48 (73.99                                                                        8.10 7.84                                                                           18.45 18.17)                         88    CH.sub.3                                                                          ##STR104##  H 135-6                                                                              73.30 (73.44                                                                        7.32 7.53                                                                           18.81 19.03)                         89    CH.sub.3                                                                          ##STR105##  H 52-3 74.14 (74.50                                                                        8.24 8.13                                                                           17.06 17.38)                         90    CH.sub.3                                                                          ##STR106##  H 101   72.50 (72.15                                                                       7.00 6.81                                                                           21.07 21.04)                         91    CH.sub.3                                                                          ##STR107##  H 76-79                                                                              n.m.r. (CDCl.sub.3) δ = 2.3 (s, 6H-2                                    Aromatic CH.sub.3 's 3.5 (s, 3H NCH.sub.3)       92    CH.sub.3                                                                          ##STR108##  H 79-80                                                                              74.12 (74.00                                                                        7.81 7.84                                                                           18.22 18.17)                         93    CH.sub.3                                                                          ##STR109##  H  91  73.26 (73.44                                                                        7.67 7.53                                                                           18.88 19.03)                         __________________________________________________________________________     The products of Examples 90 to 92 were identical to the products of           Examples 1, 2 and 16 respectively.?                                      

EXAMPLE 94

The constituents of an emulsifiable concentrate are as follows:

    ______________________________________                                        5-(2,4-Dimethylphenyl)-3-methyl-1-                                            (2-pyridyl)-1,3,5-triazapenta-1,4-diene                                                             5-75% w/v                                               Emulsifier(s)         up to 20% w/v                                           Antioxidant(s)        up to 0.1%                                              Mixed hydrocarbon solvent                                                                           balance to 100%                                         ______________________________________                                    

The concentrate is prepared by mixing the emulsifier(s), antioxidant(s)and solvent until homogeneous, adding the triazapentadiene and stirringuntil dissolution occurs.

Preparation of Starting Materials

The following examples, in which all temperatures are in ° C.,illustrate the preparation of certain of the starting materials:

EXAMPLE I ##STR110##

A solution of 3-aminoquinoline (5.8 g, 0.04 m) in dry ether was treatedwith hydrogen chloride gas and the resulting monohydrochloride saltobtained by filtration. A suspension of this salt and p-toluenesulphonylchloride (7.2 g, 0.038 m) in N-methylformamide (30 ml) was stirred atroom temperature for 30 minutes then warmed to 90° on a steam bath.After 1 hour, the resulting yellow suspension was cooled and poured intoacetone (100 ml), and the insoluble solid filtered off. The solid wasthen dissolved in water, the resulting solution basified with 10N NaOHsolution, and the resulting solid extracted into chloroform. Thechloroform extract was dried and the solvent removed in vacuo to yieldan almost colourless solid which cystallised from chloroform/40°-60°petroleum ether to give N-methyl-N'-(3-quinolyl)-formamidine, (5.5 g,95%) of m.p. 142°-143°.

Analysis: Found: C, 71.08; H, 5.78; N, 22.99%. Required for C₁₁ H₁₁ N₃ :C, 71.30; H, 5.98; N, 22.67%.

EXAMPLES II TO V

The following formamidines were prepared by procedures similar to thatof Example I, starting with N-methylformamide and the appropriate amineof the formula R³.NH₂.

    __________________________________________________________________________    R.sup.3 . NCHNH . CH.sub.3                                                                               n.m.r. or                                                                     Analysis %                                                              m.p.  (Theoretical in brackets)                          Compound                                                                            R.sup.3        (° C)                                                                        C   H   N                                          __________________________________________________________________________    II                                                                                   ##STR111##    oil   n.m.r. (CDCl.sub.3): δ = 3.00 (s, N .                                   CH.sub.3), 6.3 (s, NH . CH.sub.3) 7.66 (s,                                    NCHN).                                             III                                                                                  ##STR112##    142-144                                                                             66.07 (66.23                                                                      8.17 8.03                                                                         25.19 25.74)                               IV                                                                                   ##STR113##    106-9 49.37 (49.57                                                                      4.61 4.75                                                                         24.62 24.77)                                      ##STR114##    105-6 54.67 (55.37                                                                      6.52 6.71                                                                         21.30  21.52)                              __________________________________________________________________________

EXAMPLE VI ##STR115##

A solution of 3-aminopyridine (20.0 g, 0.21 m) in excess triethylorthoformate (100 ml) and ethanolic hydrogen chloride (0.3 ml) washeated under reflux for 72 hours. Ethanol and excess triethylorthoformate were then removed by distillation over a period of 5 hours.Solid potassium carbonate (100 mg) was added to the residue, and thelasttraces of triethyl orthoformate were removed in vacuo. The residuewas then distilled under reduced pressure to yield the desired imidoester, ethyl N-(3-pyridyl)-formimidate, as a colourless liquid, (b.p.62°/0.5 mm)(24 g, 75%), n.m.r. (CDCl₃): δ = 1.4 (t, --CH₂ CH₃), 4.32 (q,--CH₂ CH₃), 7.73 (s, --N═CH--O).

The preparation of this compound is also described in J. Prakt. Chem.,313, 179 (1971). ##STR116##

The imido ester prepared in part (a) above was added to a solution ofmethylamine in ethanol (33% w/w) at -10°, and the resulting solution wasthen allowed to attain room temperature (25°). After standing overnight,the solvent and excess methylamine were removed at 40° in vacuo to yieldthe N-methyl-N'-(3-pyridyl) formamidine (15 g) as a colourless liquid.n.m.r. (CDCl₃); δ = 3.00 (s, --N.CH₃), 7.66 (S,--N═CH-N).

The preparation of this compound is also described in J. Prakt. Chem.,314, 627 (1972).

EXAMPLES VII TO LVIII

The following imido esters were prepared by procedures similar to thatof Example VI part (a), starting from the appropriate amine of theformula R³.NH₂ and ester of the formula R⁴.O(OC₂ H₅)₃.

    __________________________________________________________________________     ##STR117##                                                                                           B.P.                                                  Compound                                                                            R.sup.3      R.sup.4                                                                            (° C)                                                                          n.m.r.                                        __________________________________________________________________________    VII*                                                                                 ##STR118##  H    60° /2 mm                                                                      n.m.r. (CDCl.sub.3): δ = 1.4 (t,                                        CH.sub.2 CH.sub.3), 4.40 (q, CH.sub.2                                         CH.sub.3), 8.32 (s, NCHO)                     VIII*                                                                                ##STR119##  H    66° / 0.5 mm                                                                   n.m.r. (CDCl.sub.3): δ = 1.35 (t,                                       CH.sub.2 CH.sub.3),  4.35 (q, CH.sub.2                                        CH.sub.3), 7.72 (s, NCHO)                     IX                                                                                   ##STR120##  CH.sub.3                                                                           64° / 0.5 mm                                                                   n.m.r. (CDCl.sub.3): δ = 1.35 (t,                                       CH.sub.2 CH.sub.3), 4.25 (q, CH.sub.2                                         CH.sub.3), 1.87 (s, CCH.sub. 3)                      ##STR121##  C.sub.2 H.sub.5                                                                    70° / 0.4 mm                                                                   n.m.r. (CDCl.sub.3): δ = 1.35 (t,                                       OCH.sub.2 CH.sub.3), 4.25 (q, OCH.sub.2                                       CH.sub.3), 2.15 (q, CCH.sub.2 CH.sub.3),                                      1.10 (t, C . CH.sub.2 CH.sub.3)               XI*                                                                                  ##STR122##  H    66° / 0.1 mm                                                                   n.m.r. (CDCl.sub.3): δ = 1.38 (t,                                       CH.sub.2 CH.sub.3), 4.35 (q, CH.sub.2                                         CH.sub.3), 8.32 (s, NCHO)                     XII                                                                                  ##STR123##  H    60° / 0.1 mm                                                                   n.m.r. (CDCl.sub.3): δ = 1.4 (t,                                        OCH.sub.2 CH.sub.3), 4.38 (q, OCH.sub.2                                       CH.sub.3), 8.25 (s, NCHO)                     XIII                                                                                 ##STR124##  H    120° / 0.22 mm                                                                 n.m.r. (CDCl.sub.3): δ = 1.4 (t,                                        CH.sub.2 CH.sub.3), 4.4 (q, CH.sub.2                                          CH.sub.3), 7.7 (s, NCHO)                      XIV                                                                                  ##STR125##  H    56° / 0.08 mm                                                                  n.m.r. (CDCl.sub.3): δ = 1.25 (t,                                       CH.sub.2 CH.sub.3), 4.30 (q, CH.sub.2                                         CH.sub.3), 8.3 (s, NCHO)                      XV                                                                                   ##STR126##  H    60-62° (m.p.)                                                                  n.m.r. (CDCl.sub.3): δ = 1.4 (t,                                        CH.sub.2 CH.sub.3), 4.45 (q, CH.sub.2                                         CH.sub.3), 8.4 (s, NCHO)                      XVI                                                                                  ##STR127##  CH.sub.3                                                                           88°  at 0.2 mm                                                                 n.m.r. (CDCl.sub.3) δ = 1.3 (t,                                         CH.sub.2 CH.sub.3)  4.25 (q, CH.sub.2                                         CH.sub.3) 2.1 (s, CCH.sub.3)                  XVII                                                                                 ##STR128##  H    165° at 0.05 mm                                                                n.m.r. (CDCl.sub.3) δ = 1.4 (t,                                         CH.sub.2 CH.sub.3) 4.3 (q, CH.sub.2                                           CH.sub.3) 1.2 (t, [OCH.sub.2 CH.sub.3                                         ].sub.2) 3.65 (q, [OCH.sub.2 CH.sub.3                                         ].sub.2)                                      XVIII                                                                                ##STR129##  H    MPt. 85°                                                                       n.m.r. (CDCl.sub.3) δ = 1.4 (t,                                         CH.sub.2 CH.sub.3)  4.4 (q, CH.sub.2                                          CH.sub.3)                                     XIX                                                                                  ##STR130##  CH.sub.3                                                                           145°  at 0.3 mm                                                                n.m.r. (CDCl.sub.3) δ = 1.3 (t,                                         CH.sub.2 CH.sub.3)  4.3 (q, CH.sub.2                                          CH.sub.3) 2.2 (s, CCH.sub.3)                  XX                                                                                   ##STR131##  CH.sub.3                                                                           78° at 0.1 mm                                                                  n.m.r. (CDCl.sub.3) δ = 1.3 (t,                                         CH.sub.2 CH.sub.3)  4.3 (q, CH.sub.2                                          CH.sub.3) 2.2 (s, CCH.sub.3)                  XXI                                                                                  ##STR132##  CH.sub.3                                                                           54-6° at 0.1 mm                                                                n.m.r. (CDCl.sub.3) δ = 1.4 (t,                                         CH.sub.2 CH.sub.3)  4.3 (q, CH.sub.2                                          CH.sub.3) 2.0 (s, CCH.sub.3)                  XXII                                                                                 ##STR133##  H    143-7° at 0.3 mm                                                               n.m.r. (CDCl.sub.3 ) δ = 1.4 (t,                                        CH.sub.2 CH.sub.3) 4.4 (q, CH.sub.2                                           CH.sub.3) 8.45 (s, NCHO)                      XXIII                                                                                ##STR134##  CH.sub.3                                                                           MPt. 81-2°                                                                     n.m.r. (CDCl.sub.3) δ = 1.35 (t,                                        CH.sub.2 CH.sub.3) 4.3 (q, CH.sub.2                                           CH.sub.3) 2.0 (s, CCH.sub.3)                  XXIV                                                                                 ##STR135##  H    87-8° at 2 mm                                                                  n.m.r. (CDCl.sub.3) δ = 1.35 (t,                                        CH.sub.2 CH.sub.3) 4.4 (q, CH.sub.2                                           CH.sub.3)                                     XXV                                                                                  ##STR136##  CH.sub.3                                                                           86-8° at 0.1 mm                                                                n.m.r. (CDCl.sub.3) δ = 1.35 (t,                                        CH.sub.2 CH.sub.3) 4.25 (q, CH.sub.2                                          CH.sub.3) 1.85 (s, CCH.sub.3)                 XXVI                                                                                 ##STR137##  H    156-62° at 0.05 mm                                                             n.m.r. (CDCl.sub.3) δ = 1.3 (t,                                         CH.sub.2 CH.sub.3) 4.3 (q, CH.sub.2                                           CH.sub.3) 8.4 (s, NCHO)                       XXVII                                                                                ##STR138##  CH.sub.3                                                                           57-60° at 0.01 mm                                                              n.m.r. (CDCl.sub.3) δ = 1.3 (t,                                         CH.sub.2 CH.sub.3) 4.25 (q, CH.sub.2                                          CH.sub.3) 1.8 (s, CCH.sub.3)                  XXVIII                                                                               ##STR139##  H    74° at 0.1 mm                                                                  n.m.r. (CDCl.sub.3) δ = 1.4 (t,                                         CH.sub.2 CH.sub.3) 4.4 (q, CH.sub.2                                           CH.sub.3) 8.3 (s, NCHO)                       XXIX                                                                                 ##STR140##  CH.sub.2 CH.sub.3                                                                  57-60° at 0.1 mm                                                               n.m.r. (CDCl.sub.3) δ = 1.4 (t,                                         OCH.sub.2 CH.sub.3) 4.3 (q, OCH.sub.2                                         CH.sub.3) 1.1 (t, CCH.sub.2 CH.sub.3) 1.5                                     (q, CCH.sub.2 CH.sub.3)                       XXX                                                                                  ##STR141##  H    86-90° at 0.2 mm                                                               n.m.r. (CDCl.sub.3) δ = 1.3 (t,                                         CH.sub.2 CH.sub.3) 4.3 (q, CH.sub.2                                           CH.sub.3) 8.1 (s, NCHO)                       XXXI                                                                                 ##STR142##  CH.sub.3                                                                           60° at 0.1 mm                                                                  n.m.r. (CDCl.sub.3) δ = 1.3 (t,                                         CH.sub.2 CH.sub.3) 4.3 (q, CH.sub.2                                           CH.sub.3) 2.1 (s, CCH.sub.3)                  XXXII                                                                                ##STR143##  CH.sub.3                                                                           142-4° at 0.35 mm                                                              n.m.r. (CDCl.sub.3) δ = 1.3 (t,                                         CH.sub.2 CH.sub.3) 4.3 (q, CH.sub.2                                           CH.sub.3) 2.2 (s, CCH.sub.3)                  XXXIII                                                                               ##STR144##  H    86° at 0.02 mm                                                                 n.m.r. (CDCl.sub.3) δ = 1.4 (t,                                         CH.sub.2 CH.sub.3) 4.4 (q, CH.sub.2                                           CH.sub.3) 8.4 (s, NCHO)                       XXXIV                                                                                ##STR145##  H    136° at 0.1 mm                                                                 n.m.r. (CDCl.sub.3) δ = 1.4 (t,                                         CH.sub.2 CH.sub.3) 4.35 (q, CH.sub.2                                          CH.sub.3) 8.1 (s, NCHO)                       XXXV                                                                                 ##STR146##  H    156-160° at 0.03 mm                                                            n.m.r. (CDCl.sub.3) δ = 1.35 (t,                                        CH.sub.2 CH.sub.3) 4.35 (q, CH.sub.2                                          CH.sub.3) 8.3 (s, NCHO)                       XXXVI                                                                                ##STR147##  CH.sub.3                                                                           96- 100° at 0.025 mm                                                           n.m.r. (CDCl.sub.3) δ = 1.35 (t,                                        CH.sub.2 CH.sub.3) 4.25 (q, CH.sub.2                                          CH.sub.3) 1.8 (s, CCH.sub.3)                  XXXVII                                                                               ##STR148##  H    76-82° at 0.05 mm                                                              n.m.r. (CDCl.sub.3) δ = 1.35 (t,                                        CH.sub.2 CH.sub.3) 4.3 (q, CH.sub.2                                           CH.sub.3) 7.65 (s, NCHO)                      XXXVIII                                                                              ##STR149##  H    88-90° at 0.4 mm                                                               (C, H and N analyses - theoretical in                                         brackets) 42.976.5841.62 (42.606.5541.39)     XXXIX                                                                                ##STR150##  H    150-2° at 0.01 mm                                                              n.m.r. δ  = 7.80 (s, NCH); 4.30 (q,                                     CH.sub.2 CH.sub.3) 1.35 (t, OCH.sub.2                                         CH.sub.3) 3.50 (q, CH(OCH.sub.2 CH.sub.3).                                    sub.2); 1.18 (t, CH(OCH.sub.2 CH.sub.3).su                                    b.2. Molecular mass spectra 291.              XL                                                                                   ##STR151##  H    82 at 0.75 mm                                                                         n.m.r. (CDCl.sub.3) δ = 8.24 (s,                                        NCH); 4.40 (q, OCH.sub.2 CH.sub.3); 8.3                                       (s, ArCH.sub.3 ; 1.4 (t, OCH.sub.2                                            CH.sub.3).                                    XLI                                                                                  ##STR152##  H    70-72 at 0.4 mm                                                                       n.m.r. (CDCl.sub.3) δ = 8.23 (s,                                        NCH); 4.39 (q, OCH.sub.2 CH.sub.3); = 2.5                                     (s, ArCH.sub.3); 1.39 (t, OCH.sub.2                                           CH.sub.3).                                    XLII                                                                                 ##STR153##  H    90-92  at 0.6-0.7 mm                                                                  n.m.r. (CDCl.sub.3) δ = 8.31 (s,                                        NCH); 4.40 (q, OCH.sub.2 CH.sub.3); =                                         2.34 (s, ArCH.sub.3); 1.40 (t, OCH.sub.2                                      CH.sub.3).                                    XLIII                                                                                ##STR154##  H    80-82  at 0.7 mm                                                                      n.m.r. (CDCl.sub.3) δ = 8.3 (s,                                         NCHO); 4.28 (q, OCH.sub.2 CH.sub.3); =                                        2.18 (s, ArCH.sub.3); 1.29 (t, OCH.sub.2                                      CH.sub.3).                                    XLIV                                                                                 ##STR155##  H    128 at 0.05 mm                                                                        n.m.r. (CDCl.sub.3) δ = 8.41 (s,                                        NCH); 4.52 (q, OCH.sub.2 CH.sub.3); =                                         1.46 (t, OCH.sub.2 CH.sub.3).                 XLV                                                                                  ##STR156##  H    84 at 0.5 mm                                                                          n.m.r. (CDCl.sub.3) δ = 8.58 (s,                                        NCH); 4.48 (q, OCH.sub.2 CH.sub.3); =                                         1.38 (t, OCH.sub.2 CH.sub.3).                 XLVI                                                                                 ##STR157##  H    132 at 0.4 mm                                                                         n.m.r. (CDCl.sub.3) δ = 7.8 (s,                                         NCHO); 4.4 (q, OCH.sub.2 CH.sub.3); = 1.4                                     (t, OCH.sub.2 CH.sub.3).                      XLVII                                                                                ##STR158##  H    70 at 0.4 mm                                                                          n.m.r. (CDCl.sub.3) δ = 8.16 (s,                                        NCH); 4.36 (q, OCH.sub.2 CH.sub.3) = 2.42                                     (s, ArCH.sub.3); 2.21 (s, ArCH.sub.3); =                                      1.36 (t, OCH.sub.2 CH.sub.3).                 XLVIII                                                                               ##STR159##  H    66 at 0.3 mm                                                                          n.m.r. (CDCl.sub.3) δ = 8.39 (s,                                        NCH); 4.52 (q, OCH.sub.2 CH.sub. 3) =                                         2.56-3.09 (m, ArCH.sub.2 CH.sub.3); 1.55                                      (t, ArCH.sub.2 CH.sub.3);  = 1.39 (t,                                         OCH.sub.2 CH.sub.3).                          XLIX                                                                                 ##STR160##  H    72 at 0.1 mm                                                                          n.m.r. (CDCl.sub.3) δ = 8.34 (s,                                        NCH); 4.55 (q, CH.sub.2 CH.sub.3); = 1.55                                     (t, CH.sub.2 CH.sub.3).                       L                                                                                    ##STR161##  H    75-80 at 0.2 mm                                                                       n.m.r. (CDCl.sub.3) δ = 8.32 (s,                                        NCH); 4.35 (q, CH.sub.2 CH.sub.3); = 1.35                                     (t, CH.sub.2 CH.sub.3).                       LI                                                                                   ##STR162##  H    93 at 0.2 mm                                                                          n.m.r. (CDCl.sub.3) δ = 8.29 (s,                                        NCH); 4.38 (q, OCH.sub.2 CH.sub.3) =                                          1.39 (t, OCH.sub.2 CH.sub.3).                 LII                                                                                  ##STR163##  H    60-62 (m.p.)                                                                          n.m.r. (CDCl.sub.3) δ = 8.44 (s,                                        NCH); 4.45 (q, OCH.sub.2 CH.sub.3); = 1.4                                     (t, OCH.sub.2 CH.sub.3).                      LIII                                                                                 ##STR164##  H    100-120 at 14 mm                                                                      n.m.r. (CDCl.sub.3) δ = 8.2 (s,                                         NCHO); 4.30 (q, OCH.sub.2 CH.sub.3); =                                        2.16 (s, ArCH.sub.3); 1.29 (t, CH.sub.2                                       CH.sub.3).                                    LIV                                                                                  ##STR165##  H    127 at 0.5 mm                                                                         n.m.r. (CDCl.sub.3) δ = 7.7 (s,                                         NCHO); 4.3 (q, OCH.sub.2 CH.sub.3); = 1.3                                     (q, OCH.sub.2 CH.sub.3).                      LV                                                                                   ##STR166##  H    93 at 0.2 mm                                                                          n.m.r. (CDCl.sub.3) δ = 8.29 (s,                                        NCH); 4.38 (q, OCH.sub.2 CH.sub.3); =                                         1.39 (t,OCH.sub.2 CH.sub.3).                  LVI                                                                                  ##STR167##  H    84-88 at 0.4 mm                                                                       n.m.r. (CDCl.sub.3) δ = 8.24 (s,                                        NCH); 3.57 (q, OCH.sub.2 CH.sub.3); = 2.2                                     (s, 2 Aromatic CH.sub.3 's); = 1.2 (t,                                        OCH.sub.2 CH.sub.3).                          LVII                                                                                 ##STR168##  H    102-104 at 0.25 mm                                                                    n.m.r. (CDCl.sub.3) δ = 7.96 (s,                                        NCH); 4.52 (q, OCH.sub.2 CH.sub.3); 1.4                                       (t, OCH.sub.2 CH.sub.3).                      LVIII                                                                                ##STR169##  H    102 at 0.1 mm                                                                         n.m.r. (CDCl.sub.3) δ = 7.66 (s,                                        NCH); 4.28 (q, OCH.sub.2 CH.sub.3) 1.32                                       (t, OCH.sub.2 CH.sub.3).                      __________________________________________________________________________     *The preparation of these compounds are also described in J.Prakt. Chem.,     313, 179 (1971).                                                         

EXAMPLES LIX TO XCVI

The following amidines were prepared by procedures similar to that ofExample VI part (b), starting from the appropriate imido ester of theformula R³.N═C(R⁴)OC₂ H₅ and methylamine.

    __________________________________________________________________________    R.sup.3 . NC(R.sup.4) . NHCH.sub.3                                                                        n.m.r. or Analysis %                                                    M.P.  (Theoretical in brackets)                         Example                                                                             R.sup.3      R.sup.4                                                                          (° C)                                                                        C    H    N                                       __________________________________________________________________________    LIX                                                                                  ##STR170##  H  --    n.m.r. (CDCl.sub.3): δ = 2.95 (s, N .                                   CH.sub.3), 8.45 (s, NCHN)                         LX                                                                                   ##STR171##  H  --    n.m.r. (CDCl.sub.3): δ = 3.02 (s, N .                                   CH.sub.3): 7.80 (s, NCHN)                         LXI                                                                                  ##STR172##  CH.sub.3                                                                         --    n.m.r. (CDCl.sub.3): δ = 2.85 (s, N .                                   CH.sub.3), 1.80 (s, NCCH.sub.3), 6.3 (s,                                      NHCH.sub.3)                                       LXII                                                                                 ##STR173##  C.sub.2 H.sub.5                                                                  --    n.m.r. (CDCl.sub.3): δ =  2.90 (s, N .                                  CH.sub.3), 2.20 (q, CH.sub.2 CH.sub.3, 1.05                                   (t, CH.sub.2 CH.sub.3)                            LXIII                                                                                ##STR174##  H  112°                                                                         n.m.r. (CDCl.sub.3): δ = 3.02 (s, N .                                   CH.sub.3), 8.42 (s, NCHN)                         LXIV                                                                                 ##STR175##  H  --    n.m.r. (CDCl.sub.3): δ = 3.00 (s, N .                                   CH.sub.3), 8.35 (s, NCHN)                         LXV                                                                                  ##STR176##  H  134-5°                                                                       40.96 (41.20                                                                       3.42 3.46                                                                          20.87 20.59)                            LXVI                                                                                 ##STR177##  H  84-85°                                                                       42.70 (42.54                                                                       5.09 5.00                                                                          29.69 29.76)                            LXVII                                                                                ##STR178##  H  132°                                                                         n.m.r. (CDCl.sub.3): δ = 3.10 (s, N .                                   CH.sub.3), 8.40 (s, NCHN)                         LXVIII                                                                               ##STR179##  CH.sub.3                                                                         129-130°                                                                     63.86 (63.64                                                                       6,46 6.16                                                                          16.63 17.13)                            LXIX                                                                                 ##STR180##  H  129-131°                                                                     49.63 (49.68                                                                       6.40 6.55                                                                          25.09 24.83)                            LXX                                                                                  ##STR181##  H  oil   n.m.r. (CDCl.sub.3) δ = 3.0 (s,                                         NHCH.sub.3 ) 7.9 (s, NCHNH) 1.2 (t,                                           [OCH.sub.2 CH.sub.3 ].sub.2) 3.6 (q,                                          [OCH.sub.2 CH.sub.3 ].sub.2)                      LXXI                                                                                 ##STR182##  H  MPt. 118°                                                                    n.m.rr. (CDCl.sub.3) δ = 3.05 (s,                                       NHCH.sub.3)                                       LXXII                                                                                ##STR183##  CH.sub.3                                                                         101-3°                                                                       62.85 (62.31                                                                       5.77 5.66                                                                          18.44 18.17)                            LXIII                                                                                ##STR184##  CH.sub.3                                                                         60-2°                                                                        49.62 (49.68                                                                       6.44 6.55                                                                          25.39 24.83)                            LXXIV                                                                                ##STR185##  H  Oil   n.m.r. (CDCl.sub.3) δ = 3.0 (s,                                         NHCH.sub.3)                                       LXXV                                                                                 ##STR186##  C.sub.2 H.sub.5                                                                  BPt. 90° at 0.04 mm                                                          n.m.r. (CDCl.sub.3) δ = 2.95 (d,                                        NHCH.sub.3) 1.25 (t, CCH.sub.2 CH.sub.3 2.4                                   (q, CCH.sub.2 CH.sub.3)                           LXXVI                                                                                ##STR187##  CH.sub.3                                                                         BPt. 90° at 0.03 mm                                                          n.m.r. (CDCl.sub.3) δ = 3.1 (d,                                         NHCH.sub.3) 2.9 (s, CCH.sub.3)                    LXXVII                                                                               ##STR188##  CH.sub.3                                                                         78°                                                                          46.25 (46.43                                                                       5.91 5.85                                                                          26.74 27.07)                            LXXVIII                                                                              ##STR189##  H  129-131°                                                                     46.81 (46.43                                                                       6.07 5.84                                                                          27.38 27.07)                            LXXX                                                                                 ##STR190##  H  145-6°                                                                       61.99 (62.31                                                                       5.52 5.66                                                                          18.16 18.17)                            LXXXI                                                                                ##STR191##  CH.sub.3                                                                         153-6°                                                                       67.66 (67.76                                                                       8.60 8.53                                                                          24.20 23.71)                            LXXXII                                                                               ##STR192##  H  81-82°                                                                       39.08 (38.95                                                                       6.56 6.54                                                                          54.57 54.51)                            LXXXIII                                                                              ##STR193##  H  --    n.m.r. δ = 7.88 (s, NCH) 2.95 (s,                                       NCH.sub.3); 3.60 (q, CH)OCH.sub.2 CH.sub.3).su                                b.2); 3.60 (q, CH(OCH.sub.2 CH.sub.3).sub.2).                                 Molecular weight from mass spectra:276.           LXXXIV                                                                               ##STR194##  CH.sub.3                                                                         77-80°                                                                       51.71 (52.43                                                                       6.74 7.15                                                                          23.08 22.93)                            LXXXV                                                                                ##STR195##  H                                                          LXXXVI                                                                               ##STR196##  H                                                          LXXXVII                                                                              ##STR197##  H        These formamidines were not characterised,                                    being used directly in the preparation of the                                 triazapentadiene product.                         LXXXVIII                                                                             ##STR198##  CH.sub.3                                                   LXXXIX                                                                               ##STR199##  CH.sub.3                                                   XC                                                                                   ##STR200##  CH.sub.3                                                   XCI                                                                                  ##STR201##  H                                                          XCII                                                                                 ##STR202##  oil                                                                              Not characterised. Used directly in the preparation                           of the triazapentadiene.                                XCIII                                                                                ##STR203##  H  82-84 64.20 (64.40                                                                       7.41 7.43                                                                          28.32 28.16)                            XCIV                                                                                 ##STR204##  H  oil   Not characterised. Used directly in the                                       preparation of the triazapentadiene.              XCV                                                                                  ##STR205##  H  82-84 64.41 (64.40                                                                       7.37 7.43                                                                          28.50 28.16)                            XCVI                                                                                 ##STR206##  81-83                                                                            71.17 (71.33                                                                        6.00 5.99                                                                          22.25 22.69)                                 __________________________________________________________________________     The preparation of these compounds is also described in J. Prakt. Chem.,      314, 627 (1972)                                                          

What is claimed is:
 1. A triazapentadiene of the formula: ##STR207##wherein R¹ is alkyl of 1 to 4 carbon atoms;R² is selected from the groupconsisting of hydrogen, chlorine, bromine, fluorine, iodine and alkyl of1 to 4 carbon atoms; R³ is pyridyl optionally containing one or twosubstituents selected from the group consisting of alkyl of 1 to 4carbon atoms, alkoxy of 1 to 4 carbon atoms, chlorine, bromine, fluorineand iodine.
 2. A triazapentadiene according to claim 1 wherein R¹ is amethyl group.
 3. A triazapentadiene according to claim 1 wherein R² is amethyl group.
 4. A triazapentadiene according to claim 1 wherein R² is achlorine atom. 5.5-(2,4-Dimethylphenyl)-3-methyl-1-(2-pyridyl)-1,3,5-triazapenta-1,4-diene.6.5-(2,4-dimethylphenyl)-3-methyl-1-(3-ethyl-pyrid-2-yl)-1,3,5-triazapenta-1,4-diene.7.5-(2,4-dimethylphenyl)-3-methyl-1-(3-methyl-pyrid-2-yl)-1,3,5-triazapenta-1,4-diene.8.5-(2,4-dimethylphenyl)-3-methyl-1-(2,6-dimethyl-pyrid-3-yl)-1,3,5-triazapenta-1,4-diene.9.5-(2,4-dimethylphenyl)-3-methyl-1-(2-chloro-pyrid-3-yl)-1,3,5-triazapenta-1,4-diene.10.5-(2,4-dimethylphenyl)-3-methyl-1-(3,6-dimethyl-pyrid-2-yl)-1,3,5-triazapenta-1,4-diene.11.5-(2,4-dimethylphenyl)-3-methyl-1-(3,5-dimethyl-pyrid-2-yl)-1,3,5-triazapenta-1,4-diene.12.5-(2,4-dimethylphenyl)-3-methyl-1-(3-n-propyl-pyrid-2-yl)-1,3,5-triazapenta-1,4-diene.13.5-(2,4-dimethylphenyl)-3-methyl-1-(3-n-butyl-pyrid-2-yl)-1,3,5-triazapenta-1,4-diene.14.5-(2,4-dimethylphenyl)-3-methyl-1-(3,4-dimethyl-pyrid-2-yl)-1,3,5-triazapenta-1,4-diene.15.5-(2,4-dimethylphenyl)-3-methyl-1-(3-ethyl-6-methyl-pyrid-2-yl)-1,3,5-triazapenta-1,4-diene.16. An acaricidal composition comprising an acaricidally effectiveamount of a compound of claim 1 and a diluent or carrier.
 17. A methodof combating ectoparasites on animals which comprises contacting saidanimals with an acaricidally effective amount of a compound of claim 1.